Radiation Safety Considerations for Nurses at Duke

Duke University Medical Center enjoys national prominence in the treatment of patients with cancer and other conditions. Radioactive materials and radiation sources are commonly employed in the diagnosis and therapy of our patients. The purpose of this page is to inform members of the Nursing staff about the impact of this care on their health and well-being, and on their interaction with their patients.

First, we offer some in-service training opportunities. Second, we will briefly review some of the practical considerations in working with diagnostic nuclear medicine patients, therapeutic nuclear medicine patients and brachytherapy (implant) patients. Finally, we will discuss some of the health and regulatory considerations and how they impact on our Radiation Safety practices here at Duke.

Patient Care In-Services

RADIATION SAFETY NARRATED PRESENTATIONS: Here are some narrated slide show presentations to help you learn the "basics" of caring for radiation patients. Brought to you by the Duke Radiation Safety Division, these presentations require Adobe Flash Player. Although most computers have Flash Player pre-installed, if you need it, you can download it for free from Adobe.

OESO ON-LINE TRAINING. Learn about radionuclide patients and get OESO training credit. After you log on to OESO, click on the link to "All Courses On-line" and select "Care of the Radionuclide Therapy Patient". "Flash" is not required for OESO training modules.

Nuclear Medicine Diagnostic Patients

Your patients may undergo imaging procedures in Nuclear Medicine while hospitalized. These procedures include bone scans, gallium scans, "MUGA" scans, PET scans and so forth. They are performed with very small ("tracer") amounts of radioactive materials. The radiation levels from these patients are negligible, and present almost no hazard. Other than "Universal Blood and Body Fluid Precautions", there are no special radiation safety considerations for interacting with these patients.

Note that "CT scans", "MRI scans", "DXA scans" and "ultrasound scans" do not involve radioactive materials at all, so these patients present no radiation hazard.

Nuclear Medicine Therapy Patients

Most of these patients are treated with radioactive iodine-131 (I-131). Iodine-131 has a half-life of 8 days and emits both beta particles and gamma rays. The beta particles are responsible for killing the tumor cells. They have such a short "range" in tissue that they do not leave the patient's body, and so present no external hazard. However, if any I-131 is unintentionally ingested, the beta particles can present an internal hazard. Because I-131 is excreted in the patient's urine, saliva and perspiration, small amounts of radioactivity may be present on surfaces in the patient's room. This "contamination" can be ingested by "surface-to-hand-to-mouth" contact.

The gamma rays have properties like x-rays. They pass out of the patient's body, and therefore present a potential external hazard to bystanders. To reduce this hazard, some patients may be housed in special lead-lined rooms on Division 9300. You can work safely with these patients by using a few simple techniques:

(1) Put on shoe covers and protective gloves before entering the patient's room.

(2) Work quickly, but effectively and courteously. Minimize your time in the room. Remember, no matter how long you are in the room, you will not receive a radiation exposure large enough to cause adverse health effects.

(5) Leave all trash, linens and food trays in the room. Upon leaving the room, remove gloves and shoe covers and place them in the trash box inside the room.

(6) After leaving the room, wash your hands.

(7) In the event of a medical emergency (Code 5) involving the patient, the patient's well-being is the primary consideration. All initial measures necessary to sustain the patient should be undertaken, regardless of radiation considerations. See our Code Blue Contingency Page for details.

It may be possible to further reduce the external hazard by using portable shields (located on 9300). In general, lead aprons are minimally effective and their routine use during ordinary caregiving is not recommended. However, during prolonged procedures at close proximity to the patient (for example, a difficult blood draw), they can reduce exposure by about 15%.

A few patients are treated with pure beta emitters such as phosphorus-32 (P-32), strontium-89 (Sr-89), yttrium-90 (Y-90) and samarium-153 (Sm-153). These patients usually do not require hospitalization for radiation protection purposes, since there is no external hazard. Use Universal Precautions when caring for these patients if they are hospitalized.

Brachytherapy (Implant) Patients

In cases where their tumors are close to accessible body cavities, oncology patients may undergo a procedure called brachytherapy, or "implant" therapy. Implant therapy is effective in some cases of uterine, prostate and lung cancer. In implant therapy, a sealed source of radioactive material, usually a gamma emitter such as cesium-137 or iridium-192, is placed in a body cavity close to the tumor and left in place for a prescribed period of time. During the time the implant is in place, staff entering the room are exposed to gamma rays and must take precautions. Once the treatment is completed and the implant is removed, the patient is no longer radioactive and presents no hazard.

(1) Put on protective gloves before entering the patient's room. Although breakage of a sealed source is an unlikely occurrence, ingestion of radioactivity is easily prevented by wearing gloves.

(2) Work quickly, but effectively and courteously. Minimize your time in the room.

(4) Leave all trash, linens and food trays in the room. Upon leaving the room, remove gloves and place them in the trash receptacles inside the room. Radiation Safety surveys all materials before they leave the room.

(5) After leaving the room, wash your hands.

In the event a source becomes dislodged, notify the Radiation Oncology resident on call immediately. Do not permit others to enter the room until the source is secured. Do not attempt to handle a dislodged implant or applicator, unless you are specially trained to do so.

Medical, Reproductive and Fertility Considerations

The potential adverse health effects of ionizing radiation have been evident since the end of the 19th century, with the discovery of x-rays and the isolation of radium. Many of the early radiologists and scientists who worked with radiation personally experienced its detrimental effects, which included leukemia, skin cancer and bone sarcomas. Controlled studies with bacteria, plants and animals showed exposure to high doses of radiation to be carcinogenic (capable of inducing cancer), teratogenic (capable of causing birth defects) and mutagenic (capable of producing genetic mutations). Studies of people exposed to radiation during atomic bombings demonstrated the ability of ionizing radiation to produce profound medical effects on the gastrointestinal and hematopietic systems. Over the past half-century, thousands of additional medical, scientific and epidemiological investigations have further increased our understanding of the biological and medical effects of ionizing radiation, and at what radiation doses these effects can be expected to occur. For this reason, we have been able to establish with some certainty the levels of exposure that can be sustained without significantly increasing the risk of harm to an individual, or his or her offspring.

Medical Considerations: Past measurements of the radiation doses accrued by nurses who work with nuclear medicine therapy or implant patients at Duke indicate that staff who work on Divisions 9300, 4100 and 7700 can expect to receive less than 200 millirem per year as a consequence of their employment. This is in addition to the "natural background" exposure of about 250 millirem per year. This is about 4% of the Federal annual occupational exposure limit (see below). This level of radiation will not result in any noticable symptoms, and is not expected to have any long-term consequences.

Pregnancy Considerations: The developing embryo/fetus is more sensitive to radiation than the adult. State and Federal law limits the radiation dose to the fetus of a declared pregnant worker to 500 millirem during the period of gestation (see "Duke and Other Internet Resources" below). If you find out you are pregnant, you should declare your pregancy as soon as possible. To declare your pregnancy, contact Employee Occupational Health and Wellness at 684-3136.

Fertility Considerations: A number of epidemiological studies have been done on populations of both men and women who were exposed to radiation doses at or below the occupational limit (5,000 millirem/yr). These studies do not demonstrate a significant increase in the risk of birth defects or other genetic defects in the offspring of these individuals. In keeping with the principle of ALARA (see below), we encourage staff who are considering having children to employ the techniques we have outlined above to minimize their radiation exposure.

Regulatory and Occupational Dose Considerations

We stated above that contact with radionuclide patients would not be expected to result in adverse health effects. Why, then, do we have the lead-lined rooms, the requirement to save trash and urine and all the other precautions involved in the care of these patients? There are several reasons for this.

First, Duke is obligated to comply with extensive State and Federal regulations regarding the possession and use of radioactive materials. These regulations are intended to protect both the general public and employees. Unlike a nuclear power plant, which can fence and secure its perimeter, Duke is an open institution that is freely accessible to patients and their visitors, as well as students and staff who do not work with radioactivity. Therefore, we must adhere to some stringent requirements which are directed toward protection of the public. By law, operations at Duke must not result in a member of the general public receiving more than one hundred millirems in one year. "One hundred millirems" is about one third the annual natural background exposure. While some patient treatments can meet this criteria, others require extra shielding. Similarly, the special collection of urine and trash is dictated by environmental concerns.

Second, Duke's Radiation Safety Committees believe that "less is more" when it comes to radiation exposure. Duke subscribes to a policy called "ALARA" -- As Low as Reasonably Achievable. By subscribing to ALARA, our Radiation Safety program strives to keep the annual radiation dose to employees below one-tenth the Federal occupational limit. The current United States annual occupational dose limit is 5,000 millirem (5 rem). Dozens of epidemiological studies have failed to demonstrate any adverse effects on health, fertility or genetic viability at or below the occupational dose limit. However, we believe that it is in the best interest of our co-workers to maintain their radiation exposure to below 500 millirem per year wherever feasible.

If you wear a personal radiation monitor ("film badge"), you can obtain your radiation dose history by contacting the Nurse Manager on your Division, or Radiation Safety. Check our Dosimetry Page for tips on how to correctly wear your badge and interpret your dosimetry reports.